In the pharmaceutical and food industries, the amorphous state of sugars is produced intentionally as an inactive excipient to stabilize active materials that have low stability in aqueous media. The amorphous state has enhanced thermodynamic properties compared to the crystalline phase. Due to the high viscosity and low molecular mobility in the amorphous glass or meta-stable liquid state (compared to crystals), preservation of bio-materials, such as protein or membrane components, is possible. Thus, extended shelf life of biologics can be achieved in the matrices of sugar glasses.
Many current biological therapeutics and bio-based medicines result in high costs for production, storage, and transport since many are stored and transported at cryogenic temperatures. Due to these costs, alternatives to cryopreservation are being sought, such as preservation of biological materials in a dry state, achieved by removing water and/or cooling the formulation to an extent to create an amorphous solid (e.g., glassy state solid) and/or meta-stable liquid. In this state degradation reactions are prevented and the extreme cryogenic temperatures for storage and transport are not needed.
However, the glassy state is thermodynamically meta-stable and tends to convert to a crystal eventually, with a rate dependent on the temperature and moisture content, which will deteriorate the quality of pharmaceuticals and food and decrease the viability of biologics. Thus, stabilization of the glassy amorphous form and other amorphous forms is desirable to preserve biomaterials and food products during storage for extended times. Some sugars have been used for preservation of biological material in a glassy state (e.g., trehalose, sorbitol, mannitol, which can form glasses at ambient conditions); however, deviations from ideal temperatures and humidities can cause samples to come out of the glassy state, which can cause problems with stability.